Datasheet

Table Of Contents
DA7280
LRA/ERM Haptic Driver with Multiple Input Triggers,
Integrated Waveform Memory and Wideband Support
Datasheet
Revision 3.0
30-Jul-2019
CFR0011-120-00
25 of 76
© 2019 Dialog Semiconductor
5.5 Wideband Frequency Control
DA7280 can be configured for wideband LRA support in DRO, RTWM, and ETWM modes. This
allows an actuator to be driven outside of resonance to create a richer user experience. In this mode
frequency tracking, Active Acceleration, and Rapid Stop features should be disabled. The accessible
frequency range becomes 25 Hz to 1000 Hz. After configuring the device, see Section 5.6, the
following applies:
In DRO mode, streaming is as described in Section 5.2.4. To change output frequency, a new value
is uploaded to LRA_PER_H and LRA_PER_L.
In RTWM or ETWM modes, the frequency information is encoded into the frames of a sequence, see
Section 5.8.3. For information on sequence playback, see Section 5.6. If a repeatable frequency is
required at the start of a sequence, the first frame of a sequence must contain frequency information.
5.6 Device Configuration and Playback
Minimal one-time setup is required to drive any given actuator. This consists of setting the chosen
actuator type with its key parameters and selecting the drive mode. The Dialog SmartCanvas GUI
automatically calculates the values required and sets the registers based on the entered actuator
datasheet parameters. If the Dialog SmartCanvas GUI is not used, follow the steps outlined in this
section.
5.6.1 Boot
DA7280 comes out of reset when a power supply is provided to the device and boots for 1.5 ms. This
is followed by entry to the Inactive mode where the device is kept in its lowest power state.
5.6.2 Actuator Setup
The following setup procedure needs to be observed to program DA7280 to work with a specific
actuator:
1. Choose the correct actuator type using ACTUATOR_TYPE, 0 = LRA and 1 = ERM.
2. Choose the correct nominal maximum voltage across the actuator by checking the actuator
datasheet for the maximum allowed RMS voltage and writing the value to
ACTUATOR_NOMMAX. The allowable range is between 0 V and 6 V in 23.4 mV steps. The
ACTUATOR_NOMMAX setting can be calculated using the following formula:
󰇟 󰇠

 

(1)
3. Choose the correct absolute maximum peak voltage across the actuator by checking the actuator
datasheet and writing the value to ACTUATOR_ABSMAX. The allowable range is between 0 V
and 6 V in 23.4 mV steps. The ACTUATOR_ABSMAX value can be calculated using the
following formula:
󰇟 󰇠

 

(2)
4. Program the IMAX value (in units of mA) for the actuator using the following formula:
󰇟 󰇠



where I
max_actuator_mA
is the actuator max rated current in mA, as listed in its datasheet.
Note that in general this should slightly exceed the ACTUATOR_ABSMAX voltage
divided by the actuator impedance.
(3)
5. Program the impedance of the actuator by checking the actuator datasheet and calculating the
values for V2I_FACTOR_H and V2I_FACTOR_L using the following formulae: